1. Field of the Invention
The present invention relates to a control system for an internal combustion engine and a controlling method for an internal combustion engine and in particular to a technique of detecting failure of a direct injector in an internal combustion engine that is provided with the direct injector and a port injector.
2. Description of Related Art
An internal combustion engine has been known that is provided with: a direct injector for directly injecting fuel into a combustion chamber; and a port injector for injecting the fuel into an intake passage. Japanese Patent Application Publication No. 2011-099401 (JP 2011-099401 A) discloses that, in such an internal combustion engine, a fuel injection amount and an air-fuel ratio are learned during execution of fuel injection only by the direct injector, and the fuel injection only by the direct injector continues until the learning is completed. In addition, Japanese Patent Application Publication No. 2013-036441 (JP 2013-036441 A) discloses an internal combustion engine that includes an exhaust gas recirculation (EGR) system that can introduce exhaust gas into an intake passage.